The Federal Bureau of Investigation is searching Solyndra’s headquarters this morning, though it declined to say what it’s looking for, according to local media reports, including the San Jose Mercury News and NBC Bay Area. The FBI is reportedly conducting the search as part of a joint investigation by the U.S. Department of Energy and the Office of Inspector General.

In case you haven’t been following Solyndra, here’s the back story: Solar panel maker Solyndra, based in Fremont, Calif., filed for bankruptcy two days ago and announced a suspension of manufacturing and a layoff of 1,100 workers last week. The company is now infamous for having drawn down most of a $535 million loan from the federal government, and raising $1 billion private financing, but it wasn’t able to compete with rivals with cheaper products and more financial heft.

The Office of Inspector General is the investigative arm of the DOE and regularly audits and otherwise looks into whether the DOE is doing a good job carrying out programs and spending public money. The FBI’s involvement likely has to do with the agency’s ability to execute search warrants for a government investigation, civil or criminal. Bringing the FBI in certainly indicates a higher level of scrutiny by the DOE to determine why Solyndra didn’t accomplish the goal it set out to achieve with the government loan.

In its bankruptcy filing earlier this week, Solyndra said it wanted to look for a buyer which would be able re-start manufacturing rather than having to sell the company assets to different buyers. During a bankruptcy court hearing yesterday, the company’s chief financial officer, W.G. Stover, indicated there might be two potential bidders, Bloomberg reported.

U.S. Justice Department attorney Matthew Troy then voiced concerns that a new buyer could move the technology and equipment out of the U.S., and that would violate the terms of a federal $535 million loan secured by Solyndra to build a new factory.

NBC sent us this video footage of the interview with the FBI outside of Solyndra’s headquarters: